JPH0710339Y2 - Light amount diaphragm device for camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a light amount diaphragm device for a camera such as a video camera.

[Conventional technology]

An example of this type of diaphragm device is shown in Japanese Utility Model Laid-Open No. 60-135729. This diaphragm device includes a main plate 303 having light receiving openings 301 and 302 facing each other as shown in FIG.
A plurality of diaphragm blades 305 are arranged between the pressing plate 304 and the pressing plate 304 so as to surround the light receiving openings 301 and 302.
It is opened and closed by the drive of 6 to adjust the size of the opening diameter.

Such a diaphragm device has problems such as a hunting phenomenon in which a blade vibrates in small steps and an image fluctuates at the time of a so-called small diaphragm with a small aperture, and light diffracts to reduce the resolution.

In order to solve this problem, a filter 307 is provided to gradually face the light receiving openings 301 and 302 and adjust the amount of light as the diaphragm blade 305 is narrowed down to a small diaphragm state.

Then, when the blade 305 is opened, the filter 307 presses the pressing plate 30.
The retracting portion 308 of the filter 307 is provided in the light receiving opening 302 of the pressing plate 304 so as not to come into contact with 4.

[Problems to be solved by the device]

However, since the surface of the filter 307 is smooth, the received light is likely to be reflected, the amount of received light is reduced,
A phenomenon called shading occurs in which a part of the shape is slightly generated in the image captured by the video camera, which leads to deterioration in image quality.

This is a problem to be considered when developing a specific model, but when deploying a diaphragm device developed for a certain video camera model to other models, it can be placed before and after the diaphragm device mounted on the lens barrel of the developed model. If the distance to the arranged lens, the type of lens, the sensitivity of photoelectric conversion element such as CCD that converts the light passing through the diaphragm device to an electric signal has changed, the above problems that did not occur in the developed model It may occur in the deployment model.

[Purpose of device]

An object of the present invention is to obtain a diaphragm device for a camera whose image quality can be easily improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, the diaphragm device of this embodiment includes a guide plate, for example, a base plate 1, two diaphragm blades 3 and 5 mounted on the base plate 1, and these diaphragm blades 3 and 5. A guide plate for covering, for example, a pressing plate 7, and a driving device 9 for driving the diaphragm blades 3, 5.
It has and.

As shown in FIG. 3, the main plate 1 has a light receiving opening 12 provided at the center.
And a recess 13 (retraction part) connected to the light receiving opening 12,
A plurality of side walls 14 provided around the periphery and a bending operation hole 15
And the arc-shaped actuating hole 16 and the mounting holes 18 and 19 of the drive unit 9.
A drive hole 43, fixing holes 22 and 23 of the pressing plate 7, guide portions for guiding the diaphragm blades 3 and 5, for example guide pins 24 and 25, a mounting hole 20 for a shaft 102, which will be described later, and an operating hole 15. Ribs 28 provided outside to support the diaphragm blades 5, ribs 30 and 31 provided between the operating holes 15 and 16 to support the diaphragm blades 3, and the guide pin 2
A rib 32 that is provided close to 5 and that supports the diaphragm blades 5,
Ribs 33, 34 provided between the guide pins 24, 25 for supporting the diaphragm blades 3, fixing holes 35, 36 to the lens barrel, and the engaging projection 1
It has 7,21 and.

When the diaphragm blade 5 is attached to the base plate 1 side of the diaphragm blade 3 with respect to the concave portion 13, that is, the front and back sides of the diaphragm blades 3 and 5 are reversed, and the filter 55 described later is directed to the base plate 1 side to diaphragm the diaphragm blade 5. The filter 55 is provided to escape the filter 55 when mounted on the base plate 1 side of the blade 3. Here, when the diaphragm blade 5 to which the filter 55 is attached is mounted closer to the main plate 1 side than the diaphragm blade 3, the ribs 28 and 32 support the diaphragm blade 3 and the ribs 30 and 3
1, 33, 34 support the diaphragm blades 5.

The ribs 28, 30, 31, 32, 33, 34 project toward the pressing plate 7, and the ribs 28, 32 are formed higher than the ribs 30, 31, 33, 34.

As shown in FIG. 5, the diaphragm blade 3 engages with the guide pin 24 and has a guide portion parallel to the side edge, for example, a guide hole (oblong hole) 51 and an engagement provided diagonally with respect to the guide hole 51. For example, a pin hole 53 and a diaphragm aperture 54 provided in the center and having an acute angle portion 60 and an arc portion 52 are provided.

As shown in FIG. 6, the diaphragm blade 5 engages with the guide pin 25 and has a guide portion parallel to the side edge, for example, a guide hole (oblong hole) 57 and an engagement provided diagonally with respect to the guide hole 57. Portion, for example, a pin hole 59, a diaphragm opening 56 provided in the central portion and having an acute angle portion 61 and an arc portion 58, and a filter 55 having a slit 62 and attached in the vicinity of the acute angle portion 61 with an adhesive agent 10. .

As shown in FIG. 4, the pressing plate 7 has a light receiving opening 70 facing the light receiving opening 12 of the main plate 1, a cutout portion 75 (retraction portion) for escaping the filter 55, and an operation facing the operation holes 15 and 16. Hole 71,
72, holes 73 and 74 facing the fixing holes 22 and 23, and the guide pin 2
Pin holes 77, 78 facing 4,25, ribs 81, 82 provided to the periphery of the operation holes 71, 72 and the light receiving opening 70, and the operation holes 71,
Ribs 83 connected to the light receiving opening 70 between 72, ribs 85 and 86 connected to the pin holes 77 and 78, and between the cutout portion 75 and the pin hole 78. Ribs 87 and engaging protrusions
And engaging portions 79 and 80 having holes 41 and 42 that engage with 17, 21 respectively.

The ribs 81, 82, 83, 85, 86, 87 project toward the main plate 1 side.

The pressing plate 7 configured in this way engages the engaging portions 79 and 80 with the engaging protrusions 17 and 21 of the main plate 1 as shown in FIG.
The screws 91 and 92 are attached to the holes 22 and 23 from 4 by screwing.

As shown in FIG. 2, the driving device 9 includes a driving unit 9A and an operating unit 9B.

The driving unit 9A includes a magnet having a rotating shaft 100 and a coil for rotating the magnet, and the mounting hole 1 is provided via the mounting units 127 and 128.
It is fixed to 8,19 with screws 125,126.

The operating portion 9B is attached to the rotary shaft 100 of the drive unit 9 as shown in FIG. 10, and the distance from the rotary shaft 100 is shorter at one end than at the other end and the operating region is contained in the main plate 1.
101 and an operating lever 103 rotatable about a shaft 102 fixed in the mounting hole 20.

The operating lever 101 is provided with a balance weight 104 at one end and a pin 105 at the other end.

The operating lever 103 is provided at one end with an engaging portion that engages with the pin hole 59 of the diaphragm blade 5, for example, an elongated hole 107 with which the drive pin 106 and the pin 105 are engaged, and at the other end with the pin hole 53 of the diaphragm blade 3. An engaging portion that engages, for example, a drive pin 108 is provided.

In such a structure, the diaphragm device is inserted into the lens barrel of the camera across the optical path and fixed to the lens barrel through the holes 35 and 36 with screws.

In such a state, when the drive device 9 is driven and the operating lever 101 is rotated counterclockwise in FIG. 10, the pin 105 moves in the elongated hole 107. Therefore, the actuating lever 103 moves the shaft 102
Rotate clockwise around.

Therefore, the diaphragm blade 3 closed as shown in FIG. 7 is guided by the guide pin 24 to move to the left side as shown in FIGS. 8 and 9, and the diaphragm blade 5 is guided by the guide pin 25 as shown in FIG. To form the set aperture size.

When the drive device 9 is reversely excited, the diaphragm blades 3 and 5 move in opposite directions and are closed.

According to the embodiment described above, the guide pin 24 is provided on one side in the width direction of the main plate 1, the guide pin 25 is provided on the other side in the width direction, and the guide pin 24 is engaged on the one side in the width direction of the diaphragm blade 3. A guide hole 51 to be fitted and a pin hole 53 to be engaged with the drive pin 108 of the actuating lever 103 are provided on the other side in the width direction, and a guide hole 57 and a width to be engaged with the guide pin 25 on one side in the width direction of the diaphragm blade 5 are provided. Drive pin 106 of actuating lever 103 on the other side in the direction
Since the pin hole 59 that engages with is provided, one side in the width direction of the diaphragm blades 3, 5 is driven by the drive pins 106, 108, and the other side in the width direction is guided by the guide pins 24, 25 at an arbitrary angle. Even when the drive pins 106 and 108 move in an arc shape when the drive device 9 is driven, the drive pins 106 and 108 rotate in the pin holes 53 and 59, and the guide pins 24 and 25 move in the guide holes 51 and 57, The diaphragm blades 3 and 5 move while changing the angle.

Therefore, even if the drive pins 106 and 108 move in an arc shape, the diaphragm blades 3 and 5 are not twisted, and the diaphragm blades 3 and 5 can be smoothly opened and closed.

Even if the pin holes 53, 59 of the diaphragm blades 3, 5 are round holes, the guide holes 51, 57 are long holes, so even if there are some dimensional errors, the diaphragm blades 3, 5 can be easily mounted. can do.

Furthermore, the distance from the rotary shaft 100 of the operating lever 101 to one end is made shorter than the distance to the other end, the balance weight 104 is attached to one end, and the operating region of the operating lever 101 is housed in the main plate 1 plate. Since the actuation lever 103 is driven by the rotation of 101, the weight balance between the one end side and the other end side of the actuation lever 101 is ensured, and the actuation lever 101
Can be driven stably.

For this reason, the operating lever 101 is substantially balanced around both sides of the rotary shaft 100 of the drive device 9, so that the operating levers 101 and 103 are less likely to rotate due to vibration and the like, and the aperture blades 3 and 5 are opened and closed. The amount is difficult to change.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above embodiment, the guide holes 51, 57 and the pin holes 53, 5 are formed in the diaphragm blades 3, 5.
9 is provided, and the guide pins 24 and 25 and the operating lever 103 are provided on the main plate 1.
Although the drive pins 106 and 108 are provided in the above, the guide pins and the drive pins are provided in the diaphragm blades 3 and 5, the guide holes that engage with the guide pins are provided in the main plate 1, and the pin holes that engage with the drive pins are provided in the operating lever 103. May be provided.

[Effect of device]

According to this invention, a filter for adjusting the light amount is attached to one of the surface of the blade on the side of the main plate facing the main plate and the surface of the blade on the side of the pressing plate facing the pressing plate, and a filter for adjusting the amount of light is attached. When the blades are mounted with the filter side facing toward the main plate side or the pressing plate side, a retracting part for the filter to retract is provided in both the light receiving openings of the main plate and the pressing plate, and on the blade facing surface of the main plate and the pressing plate. Since the ribs that support the blades are provided to project toward the blades, the filter can be installed in the light receiving opening regardless of whether the blade with the filter is attached with the surface of the filter facing toward the ground plate side or the pressing plate side. The blades move smoothly without contact, and even when evaluating the image during the development process of the diaphragm device or when expanding the diaphragm device developed for a specific model to other models, the image can be viewed while viewing the captured image. Can be selected to place the filter to have ways, easily able to cope with the improvement of image quality, it is not necessary to redesign the main plate and holding plate, which is economical.

[Brief description of drawings]

1 to 11 show one embodiment of the present invention,
Each figure represents the following: 1 is a front view of the diaphragm device, FIG. 2 is a side view of the diaphragm device, FIG. 3 is a diagram showing the structure of the base plate 1, FIG. 4 is a diagram showing the structure of the pressing plate 7, FIG. 5 and FIG. Figure 6 shows two diaphragm blades
FIGS. 7 to 9 are diagrams showing the shapes of the blades 3 and 5, FIGS. 7 to 9 are diagrams showing the movement of the diaphragm blades 3 and 5, and FIGS. 10 and 11 are diagrams showing the movement of the drive device 9. FIG. 12 is a diagram for explaining the conventional technique. 1 ...... Base plate 3, 5 ...... Aperture blade 7 ...... Press plate 9 ...... Drive device 12 ...... Light receiving opening 24, 25 ...... Guide pin 51, 57 ...... Guide hole 53, 59 ...... Pin hole 101, 103 ...... Actuating lever 106,108 ...... Drive pin

Claims (1)

[Scope of utility model registration request] 1. A ground plate and a pressing plate, which are arranged opposite to each other, having (a) light receiving openings facing each other, and (b) a light receiving opening supported between the ground plate and the pressing plate so as to be movable in mutually opposite directions. Two blades having a diaphragm opening that regulates the amount of light passing through, and (c) a drive device that is attached to the base plate and that moves the two blades to adjust the opening area formed by the diaphragm opening. (D) In the camera light quantity diaphragm device mounted on the lens barrel, (e) one of the base plate facing surface of the base plate side blade and the press plate facing surface of the press plate side blade When a filter for adjusting the amount of light is attached so as to face the aperture opening, and (f) and the blade to which the filter is attached is attached with its filter side surface facing the main plate side or the pressing plate side, Is evacuated A retracting portion is provided in the light receiving openings of both the base plate and the pressing plate, and (g) ribs protruding toward the blade supporting the blade are provided on the blade facing surfaces of the base plate and the pressing plate. A light amount diaphragm device for a camera.